A liquid crystal display device is composed of a liquid crystal display element interposed between a pair of glass substrates, for example. Owing to the characteristics such as being thin, lightweight, and low in power consumption, such liquid crystal display devices are used in products such as car navigation devices, electronic books, photo frames, industrial equipment, televisions, personal computers, smartphones, and tablet terminals, and have become indispensable for everyday life and business. In these applications, investigations have been made on liquid crystal display devices of various modes pertaining to electrode arrangement and substrate design to vary optical characteristics of a liquid crystal layer.
Recent display systems of liquid crystal display devices include a vertical alignment (VA) mode such as a multi-domain vertical alignment (MVA) mode, in which liquid crystal molecules having negative anisotropy of dielectric constant are aligned perpendicularly to substrate surfaces; and an in-plane switching (IPS) mode and fringe field switching (FFS) mode in each of which liquid crystal molecules having positive or negative anisotropy of dielectric constant are aligned in parallel with the substrate surface and a transverse electric field is applied to a liquid crystal layer.
In particular, the FFS mode is a liquid crystal mode that is used widely in recent years for smartphones and tablet terminals. As the FFS mode liquid crystal display device, for example, there is disclosed (see, for example, Patent Literature 1) an FFS mode liquid crystal display device comprising: a first and a second transparent insulating substrates arranged opposite to each other with a predetermined distance, with a liquid crystal layer including a plurality of liquid crystal molecules interposed between them; a plurality of gate bus lines and data bus lines formed on the first transparent insulating substrate and arranged in a matrix form to define a unit pixel; a thin-film transistor formed at an intersection of the gate bus line and the data bus line; a counter electrode disposed in each unit pixel, made of transparent conductor; and a pixel electrode arranged in each unit pixel to generate a fringe field together with the counter electrode, being insulated with the counter electrode and made of transparent conductor and including a plurality of upper slits and lower slits symmetrical each other with respect to long side of the pixel with a predetermined tilted angle.